<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>草元素动画测试</title>
    <style>
        body {
            margin: 0;
            padding: 0;
            height: 100vh;
            background: linear-gradient(to bottom, #87CEEB, #E0F7FA);
            overflow: hidden;
        }

        .grass-area {
            position: absolute;
            bottom: 0;
            left: 0;
            width: 100%;
            height: 30%;
            pointer-events: none;
        }

        .grass {
            position: absolute;
            bottom: 0;
            width: 60px;
            height: auto;
            transform-origin: bottom center;
        }

        .grass-1 { 
            left: 20%; 
        }
        .grass-2 { 
            left: 35%; 
            width: 45px; 
        }
        .grass-3 { 
            right: 30%; 
        }
        .grass-4 { 
            right: 15%; 
            width: 50px; 
        }

        @keyframes wind-swing {
            0% { transform: rotate(-2deg) translateY(0); }
            25% { transform: rotate(5deg) translateY(-3px); }
            50% { transform: rotate(-3deg) translateY(-1px); }
            75% { transform: rotate(4deg) translateY(-2px); }
            100% { transform: rotate(-1deg) translateY(0); }
        }

        .grass-1 {
            animation: wind-swing 4.2s infinite cubic-bezier(0.34, 1.56, 0.64, 1);
        }
        .grass-2 {
            animation: wind-swing 3.8s infinite cubic-bezier(0.34, 1.56, 0.64, 1);
            animation-delay: 0.8s;
        }
        .grass-3 {
            animation: wind-swing 4.5s infinite cubic-bezier(0.34, 1.56, 0.64, 1);
            animation-delay: 0.3s;
            transform: scale(0.9);
        }
        .grass-4 {
            animation: wind-swing 3.5s infinite cubic-bezier(0.34, 1.56, 0.64, 1);
            animation-delay: 1.2s;
        }
    </style>
</head>
<body>
    <div class="grass-area">
        <img class="grass grass-1" src="/grass.png" alt="草" />
        <img class="grass grass-2" src="/grass.png" alt="草" />
        <img class="grass grass-3" src="/grass.png" alt="草" />
        <img class="grass grass-4" src="/grass.png" alt="草" />
    </div>
</body>
</html>